Leaders influence others by two means. First one is obvious is there communication or public speaking skills. It includes their choice of their words, idioms, phrases & proverbs that they use, sequence of the points, presence of mind etc matter lot.
Leaders also influence because here the influencing factors what others talk about them. Higher the level of positive talk, higher the level of positive influence. To exercise their positive influence, leaders need to become role model. To become role model, their actions speak louder than words. This is where their ethics, values, consistency depth of the knowledge etc comes in picture.
You may develop your subject content based on the above points.
All the best!
From India, Bangalore